Had to post this even though this is an old thread. I am half way through playing Myst (10th ann. ed.) on my pc running Vista home premium with full administrator privlige. I uninstalled my version of QuickTime and then ran the game install which installs QT 6.3. I then installed the game into a created folder C:/games, not in the programs folder. To save games I 'exit' and choose 'save'. On restarting the game, I choose 'restore' from 'file' in the game menu and my saved game comes up to select. I cannot believe It has worked so well, been trying for over a year and finally fell on this solution and just wanted to share. Now on to Riven, another problematic game on Vista. Hope this helps someone.

Hey! Someone with relevant interests and useful posts! Thanks for the tip, sir.

The GoG version of Myst now (no idea when the actual update occurred) comes with an option to install a "lite" version of QuickTime 4 that will allow Myst to run properly. This means you can keep any more-recent installs of QT on your system. Before this you had to permanently roll back your QT version until you were done playing Myst.